1 Field of the Invention
This invention relates to the field of decorative jewelry items, and more particularly to jewelry rope chains constructed of link elements exhibiting attractive, decorative, and ornamental visual properties.
2 Brief Description of the Prior Art
Rope chains are a popular type of jewelry made from linking a number of standard sized generally C-shaped annular link elements together in a repetitive manner and usually soldering, welding, or otherwise bonding every two link elements together. The result is a chain that is flexible and pleasing to the eye. The link elements are typically fabricated from gold, silver, or other precious metal and may be round in cross section or may be generally rectangular in cross section with rounded corners.
When made from a length of wire having a circular cross section, compression of the wire in the manufacturing process results in flat major side surfaces and outwardly bulged side surfaces on the interior and exterior edges. This is exemplified in the cross sectional views of prior art link elements shown in FIGS. 1A and 1B, the former being solid and the latter being hollow in cross section. In these figures, it can be observed that, as suggested above, the corners 1a′ and 1c′ are quite rounded, despite the flattening of the link element, and lateral edges 1b′ and 1d′ are bulged outwardly. The overall generally annular configuration of the link elements is not complete as there must be a gap provided to permit interlinking, i.e. interconnecting, of the link elements with each other, thereby defining the aforementioned generally C-shaped configuration.
The generally C-shaped link elements are fastened together in a particular way, such that tightly interlinking annular link elements give the appearance of a pair of intertwining helical rope strands. A number of annular link elements are connected and intertwined together in a systematic and repetitive pattern of orientation, resulting in an eye-pleasing, flexible, and delicate-appearing chain that looks and feels like a finely braided double helix.
In a conventional rope chain, the orientation pattern of individual link elements making up the rope chain is repeated every several link elements, for example every six link elements, and as such, the chain is referred to as a six-link rope chain. In an improvement to the conventional basic rope chain, it is taught in U.S. Pat. No. 4,651,517 that the link elements can be constructed in different dimensions so that the pattern is repeated every four link elements or even every eight or more link elements. While the '517 patent uses a six-link rope chain as a preferred embodiment, that patent teaches the formulas for creating rope chains consisting of a repeated series of six, eight, or more link elements.
The present invention may be implemented using any number of link elements in a repeated pattern along the finished rope chain. However, a six-link chain will be specifically described and shown in the accompanying drawing, and used as an exemplary embodiment.
When forming link elements from a continuous wire source, the interior and exterior side edges exhibit outwardly bulged side surfaces, as mentioned above. The above-noted U.S. '517 patent teaches the forming of link elements from a continuous length of wire having an initial circular cross section. When cut to length and configured into an annular C-shaped link element, the major surfaces are flattened, but the sided edges are rounded, having been forced to bulge outwardly under the compressive force of a press. This is evident from FIGS. 2, 3, and 7a of the '517 patent and the description of these figures in the text. Additionally, having started from wire of circular cross section, the corners of the LE, i.e. the transitions between a flat major surface to the bulging interior and exterior edges, are by the nature of the compression process, rounded.
After assembly of a series of link elements into a jewelry rope chain, because of the overlapping of each link element relative to the link elements on either side, much of each major surface of the link elements is covered by the adjacent link element. Accordingly, any light incident on the completed rope chain will reflect primarily off of the exterior side edges of the link elements. Because of the outwardly curved surfaces of such edges, and because of the rounded corners, reflection of incident light on an assembled rope chain is disbursed in all directions within a wide angle, resulting in the intensity of reflected light at any particular angle being substantially diminished relative to the intensity of the incident light. Due to the disbursement of incident light, the chain typically lacks the sparkle and glitter generally expected of jewelry articles.
Some manufacturers of jewelry use different colored gold and silver elements to enhance the beauty of the jewelry article. Examples are: rope chains in which sets of link elements of one color alternate with sets of link elements of another color; and bracelets or necklaces constructed of interconnected twisted loops exhibiting alternating sets of colored loops along their lengths. Gold, for example, is available in at least four colors; white, yellow, rose (pink), and green.
However, in typical prior art construction techniques for producing rope chain jewelry, each link element is of a single solid color, texture, shape, and pattern, e.g., each link element may be fabricated from a solid thin wire of precious metal, such as gold, in the form of an annular ring. While an all yellow gold rope chain or an all white gold rope chain is attractive, it is otherwise uninteresting due to the monotonic nature of its unvarying coloration, texture, and/or shape along the link elements of the chain. Those prior art rope chains that do exhibit variations of colors along their lengths nevertheless are constructed of individual link elements each of which is of a single solid color, texture, shape, and/or pattern.
Other chain-like jewelry articles exhibit variations of colors along their lengths using interconnected twisted loops, but they are not regarded as rope chains as defined herein.
Additionally, prior art link elements are generally C-shaped with a constant, typically rectangular cross section. As a result, a predictable visual effect is realized when the C-shaped link elements are assembled to simulate intertwined rope helixes, i.e., simulated rope strands. While some prior art rope chains are comprised of link elements of different overall configurations, whatever cross sectional geometry is chosen for a link element, that cross sectional geometry remains constant along the length of the link element, other than for small formed notches or small flattened segments. Again, this characteristic of prior art rope chain link elements results in a predictable visual appearance of the chain when viewed from any axial position along the length of the chain, and when viewed from any side of the chain when it is rotated about its longitudinal axis.
Furthermore, after all of the link elements have been assembled into a finished rope chain jewelry item, a large percentage of the total volume of precious metal in each link element is forever hidden from view. That is, for the structural integrity of the rope chain, certain dimensional parameters have to be maintained, and there have been few attempts in the prior art of manufacturing rope chains to reduce the amount of precious metals being used, for fear of lessening or destroying the structural integrity of the finished product.